A Multilevel Superelement Technique for Damage Analysis

A multilevel superelement technique is applied to model the effects of circular voids on the effective elastic properties of a porous material. A twodimensional representative volume element with a circular void in its center is initially modeled by a superelement. A thin plate of porous material with a macrocircular hole in the center is constructed with this superelement. The finite element computation is then conducted to estimate the effective Young’s modulus, Poisson’s ratio, and the shear modulus of the material using the ABAQUS code for different void sizes. The values of the isotropic damage variables, DE and DG, under various degree of damage are hence determined. These values are compared with those calculated by using a conventional micromechanics damage model. A new isotropic damage model is proposed based on the results of this analysis. To demonstrate the applicability of this damage model, an example case of a notched cylindrical bar under tensile loading is investigated.